Nozzle for wellbore tubular

ABSTRACT

A nozzle assembly is plugged, but can be opened when the nozzle is positioned downhole. The nozzle assembly comprises: a nozzle including: a body formed of an erosion resistant material; and an orifice through the body, the orifice including a main aperture portion opening on an end of the body and a lateral aperture portion extending substantially laterally from the main aperture portion and having an opening on a side wall of the body; an orifice seal for the orifice configured to substantially seal against passage of fluid through the nozzle orifice, the orifice seal formed at least in part of a disintegrateable material and including: a barrier ring encircling the side wall and overlying the opening of the lateral aperture portion; and a plug sealing the lateral aperture.

FIELD

The invention relates to wellbore structures and, in particular, nozzles and tubulars for wellbore fluid control.

BACKGROUND

Various wellbore nozzles and tubulars are known and serve various purposes. Tubulars are employed to both inject fluids into and conduct fluids from a wellbore. Nozzles have fluid flow paths through them that control the flow and pressure characteristics of the fluid moving into or out of the tubular in which the nozzle is present.

One particularly useful nozzle is disclosed in WO 2015/089669 by the present applicant.

If a nozzled tubular is to be used in some closed string operations, the nozzles need to be initially closed but later openable. For example, nozzles may be removably sealed where the string is to hold pressure, for example where pressure actuation of tubular components is required or the tubular is intended to be circulated or floated into the well, such as to total depth.

Nozzles that are closed but later openable are required.

SUMMARY

In accordance with one aspect of the present invention, there is provided a nozzle assembly comprising: a nozzle including: a body formed of an erosion resistant material; and an orifice through the body, the orifice including a main aperture portion opening on an end of the body and a lateral aperture portion extending substantially laterally from the main aperture portion and having an opening on a side wall of the body; an orifice seal for the orifice configured to substantially seal against passage of fluid through the nozzle orifice, the orifice seal formed at least in part of a disintegrable material and including: a barrier ring encircling the side wall and overlying the opening of the lateral aperture portion; and a plug sealing the lateral aperture.

In accordance with another broad aspect, there is a method for manufacturing a sealed nozzle, the nozzle including a body formed of an erosion resistant material; and an orifice through the body, the orifice including a main aperture portion opening on an end of the body and a lateral aperture portion extending substantially laterally from the main aperture portion and having an opening on a side wall of the body and the method comprising: shrink fitting a barrier ring around the side wall of the nozzle, the barrier ring being positioned to encircle the side wall and overlie the opening of the lateral aperture portion and the barrier ring formed of a disintegrable material; and a installing a plug to seal the lateral aperture.

It is to be understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable for other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Drawings are included for the purpose of illustrating certain aspects of the invention. Such drawings and the description thereof are intended to facilitate understanding and should not be considered limiting of the invention. Drawings are included, in which:

FIG. 1 is a perspective view of a wellbore tubular;

FIG. 2 is a section along line I-I of FIG. 1;

FIG. 3 is a section through line II-II of FIG. 2;

FIG. 4 is an enlarged section through a nozzle installed in the wall of a tubular;

FIG. 5 is an exploded perspective view of the components of a nozzle to be installed in the wall of a tubular;

FIG. 6 is a perspective view of a nozzle seat;

FIG. 7 is an enlarged sectional view of a nozzle;

FIG. 8 is an enlarged section through a nozzle installed in the wall of a tubular;

FIG. 9A is a perspective view of a nozzle and FIG. 9B is a sectional view along line I-I of FIG. 9A, of a nozzle having a removable plug that configures the nozzle to hold pressure;

FIGS. 10A and 10B are a top plan view and a section along line II-II of a barrier ring useful as an orifice plug;

FIG. 11 is a sectional view is a sectional view through another nozzle having a removable plug;

FIG. 12 is an enlarged section through a tubular with the nozzle of FIG. 12 installed in the wall.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments contemplated by the inventor. The detailed description includes specific details for the purpose of providing a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.

Referring to FIGS. 1 to 3, a wellbore tubular 10 of interest for plugging is shown. The wellbore tubular is for conveying fluid into or out of a well and for permitting fluid to pass between its inner diameter and outer surface. The tubular has a durable construction and may even accommodate the significant rigors presented by handling steam flows. The wellbore tubular may be formed using various constructions. For example, the ends 10 a of the wellbore tubular may be formed for connection to adjacent wellbore tubulars. As will be appreciated, while the tubular's ends are shown as blanks, they may be formed in various ways for connection end to end with other tubulars to form a string of tubular, such as, for example, by formation at one or both ends as threaded pins, threaded boxes or other types of connections.

Wellbore tubular 10 includes a base pipe 12 with one or more ports 14 extending through the pipe sidewall. In operation, fluids may pass through ports 14 between the base pipe's inner diameter ID defined by inner surface 12 a to its outer surface 12 b. Depending on the mode of operation intended for the wellbore tubular, fluid flow can be inwardly through the ports toward inner diameter ID or outwardly from inner diameter ID to the outer surface.

The inner diameter generally extends from end to end of the tubular such that the tubular can act to convey fluids from end to end therethrough and be used to form a length of a longer fluid conduit through a plurality of connected tubulars.

The tubular may include a shield 16 mounted to base pipe 12. The shield may be positioned to overlap the ports. Shield 16 is spaced from outer surface 12 b such that a space 18 is provided between the shield and outer surface 12 b.

There are openings from space 18 to the exterior of the tubular, which is the outer surface 12 b beyond the shield. As an example, there may be openings 18 a through the shield or at the end edges 16 a of shield 16 where fluid can flow into or out of space 18. In the illustrated embodiment of FIG. 2, at least some edges 16 a of the shield are spaced from outer surface 12 b such that there are openings 18 a through which space 18 can be accessed at those edges. In some embodiments, as shown, the shield may be positioned to encircle base pipe 12 at the ports 14 and, therefore, may be shaped as a sleeve, as shown with space 18 formed as an annulus and with annular access openings 18 a at both ends of the sleeve. Filtration screen may be connected at the end of the sleeve to screen fluids passing through access openings 18 a.

The openings may take other forms in other embodiments, depending on the form of the base tubular, sleeve, and mode of operation. For example, in one embodiment, the 118 a openings may be formed in whole or in part by grooves 119 in the outer surface 112 b of the base pipe (FIG. 8).

Shield 16 may serve a number of purposes including, for example, protecting the ports from abrasion and diverting flow for fluid velocity control. For example, shield 16 diverts flow between the exterior of the tubular and ports 14, such that it must pass along outer surface 12 b of the base pipe. Flow, therefore, cannot pass directly radially between the exterior of the tubular and inner diameter ID. In particular, because shield 16 overlaps the ports, ports 14 open into space 18, flow between exterior of the tubular and the inner diameter changes direction at least once: at the intersection of port 14 and space 18. While flow through the ports 14 is radial relative to the long axis xb of the tubular, flow between the ports and the exterior of the tool is through space 18 and that flow is substantially orthogonal relative to the radial flow through ports 14.

Each port 14 has a nozzle assembly 20 installed therein. The nozzle assembly permits flow control through the port in which it is installed. With reference also to FIG. 4, a particularly useful nozzle 22 is shown.

Nozzle 22 includes an orifice 26 extending through the nozzle body through which fluid passes through the nozzle and therefore through the port. In particular, a nozzle 22 is installed in each port such that flow through the port is controlled by the shape and form of orifice.

Nozzle 22 is formed of a material that can withstand the erosive rigors experienced down hole such as via abrasive flows, high velocity flows and/or steam passing through orifice 26. Nozzle 22 may, for example, be formed of a material different, for example, harder than the material forming base pipe 12. The base pipe is, for example, usually formed of steel such as carbon steel and nozzle 22 may be formed of a material harder than the carbon steel of base pipe 12. In some embodiments, for example, nozzle 22 may be formed of tungsten carbide, stainless, hardened steel, ceramic, filled materials, etc.

Orifice 26 may be shaped to allow non-linear flow through nozzle 22. In particular, orifice 26 defines a path through the nozzle, through which fluid flows, and the path from its inlet end to its outlet end is non-linear, including at least one bend or elbow that causes at least one change in direction of the fluid flowing through the orifice. This bend may affect fluid flows in a number of ways to redirect the flow to a more favorable direction, to cause impingement of the fluid against a nozzle surface or another flow to diffuse energy from the flow, to mitigate erosive damage to certain surfaces and/or to create a back pressure to slow or otherwise control flows through the nozzle.

For example with reference also to FIG. 7, orifice 26 may include a diverting bend at y that diverts flow through the nozzle from a first direction to a second direction which is offset, out of line from the first direction. With reference to the direction of flow depicted through the nozzle of FIG. 7, the first direction is shown by arrow Fa and the second direction is shown by arrow Fb. In one embodiment, the second direction is substantially orthogonal to the first direction.

Nozzle 22 is positioned in a port and will have one end open to the inner diameter ID of the tubular and the other end open to the outer surface 12 b. Generally, the nozzle is installed so that a base end 22 a is installed adjacent and open to inner surface 12 a and an opposite end 22 b is installed adjacent and open to outer surface 12 b. Orifice 26 may be formed, therefore, to avoid straight through flow between base end 22 a and opposite end 22 b. Orifice 26, for example, may include a portion defining a main aperture 26 a and a portion defining a lateral aperture 26 b. Main aperture 26 a extends from an opening 26 a′ at a base end 22 a of nozzle 22 to an end wall 26 a″ at an opposite end 22 b of the nozzle. Lateral aperture 26 b extends from the main aperture and connects main aperture 26 a to another opening 26 b′ adjacent opposite end 22 b. Lateral aperture 26 b extends at an angle from the long axis of main aperture 26 a. The angular intersection of the axis of lateral aperture relative to the main aperture may be substantially orthogonal (+/−)45° and in one embodiment, for example, the apertures 26 a, 26 b intersect at y at substantially 90°.

The nozzle may be substantially cylindrical with ends 22 a, 22 b and substantially cylindrical side walls 22 c extending between the ends. In such an embodiment, the main aperture portion opens at an end and the pair of lateral aperture portions opens on the cylindrical side walls.

End wall 26 a″ prevents straight through flow through the nozzle and acts to divert flow from the first direction in the main aperture to the lateral direction through lateral aperture 26 b. Impingement of fluid flows against wall 26 a″ dissipates energy from the flow and concentrates erosive energy against wall 26 a″ rather than surfaces beyond the nozzle. Orifice 26 is formed through the material of the nozzle and, thus, walls 26 a″ and the other walls defining orifice 26 are of erosion-resistant material. Thus, the diverting bend and in particular end wall 26 a″, can reliably accommodate the passage therethrough of erosive flows including that of steam. This foregoing description focuses on flow in only one direction through apertures 26 a, 26 b, but it is to be understood that flow can be from opening 26 b′ to opening 26 a′ (i.e. with the flow moving in the opposite directions of arrows Fa and Fb), if desired. See for example, FIG. 8 wherein flow arrows F through nozzle 122 passes in the opposite direction from outer lateral aperture portions 126 b to main aperture portion 126 a of orifice 126.

Orifice 26 may be further configured to control the flow characteristics of fluid passing therethrough. In one embodiment, apertures 26 a, 26 b may be sized to limit the volume of fluid capable of passing therethrough. For example, apertures 26 b may be smaller diameter openings, sized to allow less flow, than aperture 26 a. For example, the total cross sectional area of apertures 26 b may be less than the total cross sectional area of aperture 26 a, such that a back pressure is created when flow is in the direction of arrows Fa, Fb.

Alternately or in addition, apertures 26 a, 26 b may be shaped to impart desired flow rate and/or pressure on the fluid passing therethrough. For example, while aperture 26 a is shown generally cylindrical, it can be shaped to generate selected flow conditions. As another example, lateral aperture 26 b, as shown, has internal shape with a jetting constriction to impart a jet effect, which generally includes a fluid acceleration and pressure change (i.e. drop), in the fluid passing therethrough. The shape of apertures 26 a may change depending on whether the flow is intended to be with arrows Fb or against them or a bidirectional jetting shape may be employed with a symmetrical constriction similar to an hour glass. The hour glass jetting constriction includes an internal frustoconical tapering wall adjacent a narrower throat and a divergent surface on the opposite side of the throat from the taper.

In addition or alternately, there may be more than one main and/or lateral aperture. For example, as shown, orifice 26 may take the form of a T-shaped conduit with at least two lateral apertures 26 b extending from the main aperture. However, while two lateral apertures 26 b are shown, there may be only one or more than two such apertures. Generally, there will be an even number of lateral apertures with pairs substantially diametrically opposed across the circumference of the main aperture 26 a. The diametric positioning, with one lateral aperture 26 b opening into main aperture 26 a at a position substantially opposite another lateral aperture 26 b (as shown in FIG. 7), allows fluid impingement when flow is inwardly from apertures 26 b to aperture 26 a. This impingement may create a desired back pressure on the flow through nozzle.

Nozzle 22 conveys fluid between openings 26 a′ and 26 b′ across the wall of the base pipe. One opening is exposed in the inner diameter of the base pipe and the other opening is exposed on outer surface 12 b. If shield 16 is employed, fluid when exiting from nozzle 22, enters annulus 18. The position of opening 26 b′ of lateral aperture 26 b causes some fluid movement parallel to outer surface 12 b, rather than straight radially out from port 14.

Nozzle 22 may be installed in any of various ways in its port 14. If desired, nozzle assembly 20 may include installation fitting 24 to hold nozzle 22 in its port 14. For example, if the material of nozzle 22 prevents reliable engagement to base pipe or is formed of a material different than the material of the base pipe, a fitting 24 may be employed to ensure a good fit of the nozzle in its port and may, for example, reduce the risk of nozzle falling out of the port.

Installation fitting 24 may be formed to fit between the nozzle and the port. For example, the installation fitting may include a portion for being engaged in the port and a portion for securing nozzle. The portion for being engaged in the port may vary depending on the form and the shape of the port and the desired mode of installation in port 14. In the illustrated embodiment, for example, installation fitting 24 includes a threaded portion 28 as that portion engageable in the port. The port may also include threads 30 into which fitting 24 may be threaded.

The portion for securing the nozzle may also vary, for example, depending on the form and shape of nozzle 22 and the desired mode of installation of nozzle 22. For example, in one embodiment, nozzle 22 can be held rigidly by the fitting and in another embodiment, nozzle may be installed have some degree of movement relative to the fitting, while being held against becoming entirely free of the fitting. Thus, as an example, fitting 24 in the illustrated example includes a passage 32 into which nozzle 22 fits. Passage 32 passes fully through the fitting such that it is open at both ends of the fitting and, in other words, the fitting is formed as a ring. When nozzle 22 is installed, opening 26 a′ is exposed at one end of the passage and opening 26 b′ is exposed at the other end of the passage.

In this embodiment, nozzle 22 is secured rigidly into passage 32. For example, nozzle 22 may be press fit and possibly mechanically shrunk fit, into passage 32. In one embodiment, fitting 24 may be heated to cause thermal expansion thereof that enlarges the diameter across passage 32, nozzle 22 may be fit therein and fitting 24 cooled to contract about the nozzle and, thereby, firmly engage it. In such an embodiment, fitting 24 may include features to modify the hoop stresses about the ring to best accommodate heating expansion for press fitting. For example, passage 32 and nozzle 22 may have a tapering diameter from end to end to facilitate press fitting these parts together. For example, nozzle 22 may have a tapering outer diameter from one end to the other and passage 32 may have a tapering inner diameter from one end to the other end. The nozzle 22 may then be inserted and forced into passage 32 with the narrow end of the nozzle wedged into the narrow end of the passage and the tapering sides of the parts in close contact. In addition or alternately, for modification of hoop strength, passage 32 may include notches 34 in the otherwise substantially circular sectional shape (orthogonal to the center axis x of passage 32).

In some embodiments, the material of nozzle 22 may have thermal expansion properties different than the material of base pipe 12. As such, if nozzle 22 was installed directly into base pipe 12, it may tend to become dislodged or damaged in use such as when in a high temperature (i.e. steam) environment. Generally, the materials most useful for the nozzle may have a low coefficient of thermal expansion, while the materials most useful for the base pipe 12 may have a reasonably high coefficient of thermal expansion and most often a nozzle firmly installed in a port at ambient temperatures may tend to fall out of a base pipe at elevated temperatures. To address issues caused by thermal expansion, installation fitting 24 may be formed of a material having a coefficient of thermal expansion selected to work well with both the nozzle and the base pipe. In one embodiment, installation fitting 24 is formed of a material having a coefficient of thermal expansion between those of the materials of the base pipe and the nozzle. In another embodiment, the coefficient of thermal expansion of fitting 24 is greater than that of base pipe 12. As such, when undergoing thermal stress, fitting 24 will undergo thermal expansion ahead of base pipe 12 and fitting 24 stays firmly engaged in port. In such an embodiment, nozzle 22 and fitting 24 can be connected when the fitting is thermally expanded.

Shield 16, if employed, may overlap the nozzle assembly to hold nozzle 22 in the port 14. In one embodiment, nozzle 22 is fit in port such that any movement to fall out of port is radially out, as may be controlled, for example, by tapering of nozzle and the port/passage in which it is installed to have the wide ends on radially outwardly positioned. Shield 16 includes a plug 36 in a hole 38 that substantially radially aligns with port 14. Plug 36 is removable to allow opening of hole 38 and access to port 14 and, thereby, installation of nozzle assembly 20 to port 14 through hole 38. After nozzle 22 is installed, plug 36 may be reinstalled in hole 38 to overlie the nozzle. Plug 36 and hole 38, for example, may be threaded to facilitate removal and reinstallation of the plug.

Plug 36 can ensure that nozzle 22 remains in position in port 14 even if nozzle 22 comes loose. For example, plug 36 can be formed to penetrate into hole 38 sufficiently to bear down on end 22 b of the nozzle. If there are tolerances that may prevent reliable fitting of the plug against end 22 b of the nozzle, a flexible spacer may be employed. For example, as shown, there may be a spring 40 between plug 36 and nozzle 22.

Nozzle assembly 20, in this embodiment including nozzle 22 and fitting 24 in port 14, allows fluid to move between inner diameter ID and outer surface 12 b through orifice 26. The lateral orifice 26 b directs fluid flows that are adjacent opening 26 b′ to pass substantially parallel to outer surface 12 b through annulus 18. To facilitate flows through the annulus with minimal erosive damage to shield 16, aperture 26 b may be positioned such that flows therethrough pass somewhat parallel to the long axis xb of base pipe. For example, the nozzle 22 can be installed such that the axis xa of aperture 26 b is within 60° and perhaps within 45° of long axis xb. In the illustrated embodiment, axis xa of aperture 26 b is substantially aligned with long axis xb.

To install a nozzle assembly in such an embodiment, plug 36 can be removed from hole 38, the nozzle assembly including at least nozzle 22 but possibly also fitting 24 can be inserted through hole 38 and installed in port 14 with openings 26 a′ and 26 b′ exposed in inner diameter ID and annulus 18, respectively, and with axis xa of aperture 26 b directed in a selected direction, for example toward the open edges 16 a of shield 16. Then plug 36 can be installed in hole 38 over nozzle 22. If there is a spacer, such as spring 40, it is positioned between nozzle 22 and plug 36. In an embodiment where the nozzle assembly includes fitting 24 and nozzle 22, these parts can be installed separately or may be connected ahead of installation.

Tubulars according to the present invention can take other forms as well. In one embodiment, as shown in FIG. 8, tubular 110 includes a screening apparatus 150. Tubular 110 is primarily useful for handling inflows, since screening apparatus 150 removes oversize particles from the flows to opening 118 a. Grooves 119 in outer surface 112 b extend under apparatus 150, through openings 118 a under an edge of the shield and into space 118 between outer surface 112 b and shield 116. Space 118 opens to nozzle. It is noted that tubular 110 illustrates a nozzle 122 without an additional installation fitting and, instead, nozzle 122 is secured directly into the material of base pipe.

During use of the tubular, fluid may pass through nozzle orifice 26 between inner diameter ID and outer surface 12 b. Nozzle 22 diverts flow such that it passes in a non-linear fashion between inner diameter ID and outer surface 12 b. Orifice 26 causes fluid flows to change direction as they pass through the nozzle including both: (i) substantially radially relative to the long axis xb of the base pipe and (ii) substantially parallel to the outer surface, which is possibly somewhat parallel to the long axis of the base pipe. This may direct flows through an annulus between outer surface 12 b and a shield 16 spaced from the outer surface. The fluid may flow through space 18, along outer surface 12 b through an opening 18 a, 118 a to the annulus about the tubular.

Flows outwardly tend not to damage structures external thereto such as external casing, sand control screen or the formation. The fluid jetting through nozzle is diverted from a radially outward direction (through aperture 26 a) to a lateral direction along the outer surface of the base pipe, which is parallel to the wellbore wall. As such, the force of the fluid passing from the tubular is dissipated at end wall 26 a″, where the flow path diverts laterally and by shield 16.

In use, nozzle 22 may control fluid flows by accommodating and avoiding erosion through ports and controlling velocity and pressure characteristics of the flow.

For example, a method for accepting inflow of steam or produced fluids in a paired, heavy oil (such as oil sand), gravity drainage well may employ a tubular such as is depicted in FIGS. 1 to 3 or FIG. 7. In paired well steam production, it is desirable that introduced steam create a steam chamber in the formation that heats the heavy oil and mobilizes it as produced fluids. The produced fluids are intended to flow into a producing well. Sometimes steam from an adjacent well may break through and seek to enter the producing well. Using a tubular, as described, steam or hot water that is close to its saturation pressure, may be restricted from passing into the tubular due to the form of the nozzle and the configuration of the nozzle in the tubular. For example if the steam chamber is close by, hot water flowing through the nozzle may flash and depending on the geometry can significantly reduce the local flow rate which is beneficial in preventing steam from even entering the screen. In particular, the limited entry size of the apertures first limits the volume of produced fluids that can pass into the tubular. Also, the impingement of flows from the diametrically opposed apertures 26 b tends to resist flows through the orifice 26 and creates a back pressure that limits flows through the nozzle. Also, the diverted flow path from aperture 26 b to aperture 26 a dissipates fluid force so that the tubular tends not to problematically erode.

During use, while forces may tend to act to dislodge nozzle from its position, the method may include holding nozzle in place against forces tending to move the nozzle into an inactive position. For example, the method may include holding the nozzle down into the port, for example, by a shield thereover. Alternately, or in addition, the method may include holding the nozzle against dislodgement by differences in thermal expansion, for example, by use of a fitting. A fitting may act between the nozzle and the base pipe to hold the nozzle in place. For example, the fitting may prevent the nozzle from passing into the inner diameter due to a taper in the parts and the nozzle may have a thermal expansion that holds nozzle in place.

While the embodiment is described wherein nozzle 22 is rigidly installed in fitting 24, the nozzle in some embodiments can be slidably mounted in the fitting. For example, nozzle can slide into and out of the fitting depending on the pressures against openings 26 a′ and 26 b′. As such, nozzle 22 can operate as a form of valve.

The foregoing nozzle performs very well to control flows through the orifice outwardly from and inwardly to the tubular. A plugged nozzle of this type has been invented to permit a tubular fit with this nozzle to hold pressure in either direction. The plug permits the nozzle to be closed initially and then will open automatically after a period of time, in some embodiments without operator manipulation.

With reference to FIGS. 9A to 12, a plugged nozzle can include a nozzle including ends 222 a, 222 b and side wall 222 c extending between the ends. The nozzle may be substantially cylindrical, in particular where side walls 222 c are shaped substantially cylindrically between ends 222 a, 222 b.

The orifice 226 through which fluid flows through the nozzle is as described above. In this illustrated embodiment, orifice 226 has a main aperture portion 226 a extending into the nozzle from an opening 226 a′ at end 222 a and at least two lateral aperture portions 226 b that have openings 226 b′ on side wall 222 c. As noted above, orifice 226 may take the form of a T-shaped conduit with the at least two lateral apertures 226 b extending substantially at 90. from, and substantially diametrically opposed across, the main aperture portion.

Nozzle 222 conveys fluid between openings 226 a′ and 226 b′ across the wall of the tubular's base pipe 212. Opening 226 a′ is exposed in the inner diameter 212 a of the base pipe and the openings 226 b′ are exposed on outer surface 212 b. If shield 216 is employed, openings 226 b′ are in annulus 218.

In order to hold pressure, orifice 226 must be sealed against fluid flow therethrough. Any such seal may be configured to hold significant pressure differentials, withstand the rigors of downhole placement and hold for a selected period of time, sometimes for days or weeks, before opening. The seal may be configured to be openable automatically or only after a manipulation by the operator.

The seal may be formed of a material that disintegrates in a suitable period of time, for example less than a month or less than a week, at either normal downhole conditions or induced downhole conditions. If a seal is needed that opens automatically, it may be selected to disintegrate at normal downhole conditions. Alternately, if the operator wants a seal that opens only when particular downhole conditions are induced, then a material may be used that disintegrates only at non-typical downhole conditions, for example in the presence of an acid. For example, seal materials may be disintegrable by intentional treatments such as conditions or chemicals specifically introduced. Such intentional treatments may introduce, for example, acid, steam or solvents. In another embodiment, the materials may disintegrate by contact with conditions or fluids normally present in downhole environments such as heat, hot water, brine, hydrocarbons, etc.

By disintegrate, it is meant that the material loses its ability to create a seal in the orifice such as, for example, by any of melting, solubilizing, crumbling, eroding, etc. In one embodiment, the material disintegrates such that it breaks down completely or to the point that any material can be washed away by fluid flow leaving the orifice substantially free of any seal material. It may be important to ensure that all of the seal material is removed if calculations used to select nozzle parameters are based on the original orifice dimensions or shape.

In one embodiment, the seal may be formed at least in part of a wax, a polymer and/or a metal alloy that disintegrates over a period of time when exposed to downhole conditions of temperature or fluid composition. Table 1 shows possible seal materials and their applications to downhole conditions.

TABLE 1 Possible Disintegrable Material for Orifice Seal Mode of Material Disintegration Considerations Wax such Dissolves in Easy to apply as micro- hydrocarbon Stable at downhole temper- crystalline Melts at high atures up to about 40 C. wax temperatures Cannot hold high ΔP (heat or steam) (>2000 psi) Brine Degrades slowly Applicable to higher Degradable in brine temperatures Polymer Some types (40 C.-100 C.+), (also called removable but ΔP resistance biopolymer) quickly with and degradation rate heat and steam is sensitive to temp Stable in hydrocarbon and acid Metal alloy Degrades quickly Insensitive to temper- and completely ature and steam in brine or acid Excellent (high) Rate of degradation ΔP resistance can be tailored

In one embodiment, the seal is formed at least in part of a brine soluble metal alloy such as a zinc aluminum alloy. In another embodiment, the seal is formed at least in part of a wax that melts at temperatures in excess of 40C. In one embodiment, the wax is used in combination with a metal alloy, wherein the wax is applied as a first layer over the metal alloy to fill pockets and thereby avoid the accumulation of debris therein. The wax also acts as a coating to protect the alloy against premature degradation. Once the wax is removed then the alloy is exposed for degradation. Other coatings are also useful to protect the alloy against premature degradation. For example, a thin gold coating may be applied over another disintegrating material. The gold dissolves slowly, but when it is removed, the underlying material, such as metal alloy may then break down quickly.

In one embodiment, orifice seal includes a barrier ring 260 and/or a plug 262, 264 in orifice 226. Ring 260 and possibly also plug 262, 264 are formed of disintegrable material.

Barrier ring 260 encircles side wall 222 c and overlies openings 226 b′. The inner diameter 260′ of the barrier ring seals against the surface of the side wall and the ring has a length L from end to end to overlie and completely cover openings 226 b′ such that the interface between the ring and the side wall creates a seal against both inward flow (i.e. collapse pressure where external pressure or pressure at 226 b′ is greater than internal pressure, which is pressure at 226 a′) and outward flow (i.e. burst pressure where external pressure, which is pressure at 226 b′, is less than internal pressure or pressure at 226 a′). Barrier ring 260 is a complete annular member and thereby offers the benefits of hoop strength to resist burst pressures through orifices 226. A single ring 260 may be positioned to cover all orifices exiting on side wall 222 c.

The orifice seal may further or alternatively include plugs 262 in orifice. In the illustrated embodiment, plugs 262 are in lateral aperture portions 226 b of the orifice. Plugs 262 may be sized to fit closely in and thereby physically block off and seal the lateral aperture portions against fluid flow therethrough.

A seal may be formed simply by plug 262 having an outer cross sectional shape selected to follow the cross section shape through lateral aperture. In particular, plug 262 may have a shape to make contact about an annular surface within the lateral aperture portion in which it is installed. In one embodiment where lateral aperture includes a jetting constriction with throat 1226 b′, the plug may be formed with a frustoconically shaped outer surface with a taper selected to substantially conform, and thereby fit such as by wedge lock, against one or both of the frustoconically shaped inner diameters adjacent the throat in the lateral aperture. As noted, a jetting constriction may have an internal frustoconical tapering wall on one or both sides of the throat and the plug may be shaped to have a taper that substantially conforms to that taper. In such an embodiment, pressure differentials across the plug may actually drive the plug into greater contact with the orifice wall due to the wedge lock effect.

Plugs 262 may be formed to have two frustoconical surfaces to act against both burst and collapse pressure or may only have one frustoconical surface, such as illustrated here, to work in either one of burst or collapse.

In one embodiment, ring 260 works very well against collapse pressure, as collapse pressure drives the ring tighter against the outer surface of the nozzle and, as such, plugs 262 have a frustoconical outer shaping diverging towards its inner end 26 a to fit against the inner taper between throat 1226 b′ and main aperture 226 a. Ring 260 therefore is beneficial when floating a string into a well. Ring 260 also prevents against unforeseen pressure surges on the outside of the tubular from entering the string inner diameter.

In one embodiment, the plugs are formed at least at their inner end 26 a to fill the space of the lateral aperture portions at least at the entrance from the main aperture 226 a such that no debris may accumulate and no pressure locks may be formed against the plugs, when fluid from the tubular inner diameter fills the main aperture. Using pressure lock as an example, a pressure lock is effectively a gas bubble and if a gas bubble formed between the fluid in the main aperture and the plugs, they may not be able to disintegrate. In the illustrated embodiment, inner ends 26 a of the plugs not only fill lateral aperture portions 226 b at their entrance from the main aperture, but also protrude back into main aperture 226 b.

In one embodiment, a plug is also installed in main aperture 226 a to ensure that main aperture does not retain debris. For example, in the embodiment of FIG. 11, plug 264 is in both main aperture 226 a and lateral apertures 226 b. While not shown, plug 264 can be used with or without the barrier ring 260 and with or without separate plugs 262 in lateral apertures 226 b.

The presence of ring 260 offers a benefit over use of plugs 262 or plug 264 alone. The ring keeps plugs 262 and 264 in place and improves resistance to pressure differentials that might otherwise cause the plugs to be expelled. For example, while plugs can be installed to wedge lock in one direction, it may be difficult to configure the plugs to resist significant pressures in both burst and collapse. Ring 260, can protect the plugs from feeling the full effect of collapse pressures and prevents the plugs in lateral apertures 226 b from moving outwardly due to burst pressures at opening 226 a′.

As noted, ring 260, plug 264 and possibly plugs 262 are formed at least in part of disintegrable material. While plugs 262 are often formed of material selected to disintegrate, they may be small enough and configured simply to be expelled after removal of the ring.

Ring 260, plug 264 and plugs 262 may be formed of the same material or different materials. The materials can be selected depending on the desired rate of disintegration, the initial wellbore conditions in which the seal is to hold pressure and the wellbore conditions in which the seal is to disintegrate, if different than the initial wellbore conditions. In one embodiment, the ring is made of a metal alloy, the plugs 262 are formed of a metal alloy the same as or different than the ring and the plug 264 is formed of a wax such as a biopolymer. In one embodiment, a wax plug is employed in main aperture 226 a while metal alloy plugs are in the lateral apertures and a metal alloy ring encircles the nozzle overlying the openings. In such an embodiment, the wax protects against debris, such as drilling mud and cuttings, accumulating in the main aperture. The wax also protects the alloy from contact with wellbore fluids. As such, only when it is desired to begin disintegration of the alloy plug will the wax be removed. The wax in that case acts like a coating to control the time at which the alloy is allowed to come into contact with the fluids that cause the alloy to disintegrate. Other coatings, such as gold, polymers, etc. that are intentionally removed or breakdown automatically can be used to cover the plug to control disintegration of the plug.

The orifice seal can be installed in various ways. A ring 260 formed of metal alloy may be installed by shrink fitting onto the outer surface of the nozzle. The plugs can be inserted into the apertures in various ways. If made of alloy, they may be inserted by casting. In one embodiment, plugs 262 for lateral apertures 226 b are in the form of solid rods and are inserted into the 226 b apertures. In one embodiment, each plug 262 is frustoconically formed and is inserted through main aperture 226 a and narrow end first into the lateral aperture until it wedge locks against the frustoconical tapering surface adjacent throat 1226 b′. In such an embodiment, the ring is installed after the plugs 262.

If a wax plug 264 or other coating is employed, it may be installed before or after the ring. In one embodiment, after the ring is installed, wax is poured into the main aperture to form wax plug 264. A coating 265 may be applied over exposed exterior surfaces of the ring and possibly over the entire outer surface of the nozzle body 222.

A plugged nozzle tubular may be useful in operations such as for example where circulation is required without a washpipe, to float the tubular into the depth of the wellbore or when requiring pressure up to set hydraulic mechanisms, such as a packers. Some of these operations only require holding minimal pressure but some pressure up operations may require holding pressure to thousands of psi such as at least 1500 psi and sometimes up to 6000 psi pressure differential. The foregoing described plugs can be configured to hold these pressures.

In use for example, a plugged nozzle tubular, with nozzle orifices configured and positioned as desired for controlling eventual in flow or outflow but initially plugged, may be run into a wellbore. The process may include:

-   -   floating in the tubular, while the plugs in the nozzle         substantially prevent leaks through the nozzles;     -   circulating through the tubular without a washpipe, while the         plugs in the nozzle substantially prevent leaks through the         nozzles;     -   pressuring up the tubular inner diameter to create a pressure         differential across the tubular wall, while the plugs in the         nozzle substantially prevent leaks through the nozzles; and/or     -   circulating one fluid out of the tubular and replacing it with         another fluid.

After one or more of these operations, the plugs may be removed to open the nozzles to controlled fluid flow through their orifices, this may include:

-   -   waiting until the plugs open automatically by residence time in         wellbore conditions;     -   removing a coating automatically or intentionally, such as         circulating heated fluid, or allowing time, to melting a wax         plug from the main aperture;     -   removing the barrier ring and applying burst or collapse         pressure to move the plugs out of the lateral apertures; and/or     -   circulating a brine into the well and into contact with the         plugs, the brine selected to disintegrate the plugs.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article “a” or “an” is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. For US patent properties, it is noted that no claim element is to be construed under the provisions of 35 USC 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or “step for”. 

1. A nozzle assembly comprising: a nozzle including: a body formed of an erosion resistant material; and an orifice through the body, the orifice including a main aperture portion opening on an end of the body and a lateral aperture portion extending substantially laterally from the main aperture portion and having an opening on a side wall of the body; and an orifice seal for the orifice configured to substantially seal against passage of fluid through the nozzle orifice, the orifice seal formed at least in part of a disintegrable material and including: a barrier ring encircling the side wall and overlying the opening of the lateral aperture portion; and a plug sealing the lateral aperture position.
 2. The nozzle assembly of claim 1, wherein the orifice seal is configured to be openable automatically by contact with intentional treatment of conditions or fluids.
 3. The nozzle assembly of any one of claim 1, wherein the orifice seal is formed at least in part of wax, polymer, or metal alloy that disintegrates when exposed to conditions of temperature or fluid composition.
 4. The nozzle assembly of any one of claim 1, wherein the orifice seal is formed at least in part of a brine soluble metal alloy.
 5. The nozzle assembly of claim 4, wherein the brine soluble metal alloy is coated with at least one coating to protect against premature degradation, the at least one coating being at least in part wax, polymer, or gold.
 6. The nozzle assembly of any one of claim 1, further comprising a main aperture plug coupled to the main aperture to prevent intrusion of debris.
 7. The nozzle assembly of any one of claim 1, wherein an inner diameter of the barrier ring seals against a surface of the side wall, the barrier ring completely covers the opening of the lateral aperture portion, and thereby creates a seal against both inward flow and outward flow.
 8. The nozzle assembly of any one of claim 1, the barrier ring being a complete annular member.
 9. The nozzle assembly of any one of claim 1, wherein one or both of the apertures has an internal shape with a jetting construction selected to impart desired flow rate and volume of fluid passing therethrough.
 10. The nozzle assembly of claim 9, wherein the jetting construction is an hour glass jetting construction, including an internal frustoconical tapering wall adjacent a narrower throat, and a divergent surface on the opposite side of the narrower throat from the internal frustoconical tapering wall; and the plug has a frustoconical outer shape diverging towards its inner end to fit between the throat and the main aperture.
 11. The nozzle assembly of any one of claim 1, wherein the plug protrudes from the lateral aperture position into the main aperture position.
 12. The nozzle assembly of any one of claim 1, further comprising a main aperture plug installed in the main aperture position, the main aperture plug being constructed of a material selected to disintegrate before the plug.
 13. A method for manufacturing a sealed nozzle, the nozzle including a body formed of an erosion resistant material; and an orifice through the body, the orifice including a main aperture portion opening on an end of the body and a lateral aperture portion extending substantially laterally from the main aperture portion and having an opening on a side wall of the body and the method comprising: installing a plug to seal the lateral aperture portion; positioning a barrier ring to encircle the side wall and overlie the opening of the lateral aperture portion, the barrier ring formed of a disintegrable metal alloy; and shrink fitting the barrier ring around the side wall of the nozzle.
 14. The method of claim 13, wherein the plug is installed by casting.
 15. The method of any one of claim 13, wherein the plug is installed by insertion.
 16. The method of any one of claim 13, wherein the barrier ring is shrink fitted by press fitting.
 17. he method of any one of claim 13, wherein the barrier ring is shrink fitted by thermal fitting.
 18. The method of any one of claim 13, further comprising installing a second plug to seal the main aperture portion; wherein the second plug is installed by insertion through the main aperture portion.
 19. The method of any one of claim 13, wherein the lateral aperture portion is frustoconically formed, having a throat; and the plug is frustoconically formed, having a narrow end, and is installed by insertion of its narrow end first into the lateral aperture portion until it wedge locks against a tapering surface adjacent the throat.
 20. The method of any one of claim 13, further comprising coating the orifice with a coating material.
 21. The method of claim 20, wherein coating is achieved by pouring a wax into the main aperture portion. 